Magnetic field and temperature-modulated photoluminescence and magneto-optical anisotropy of Sn-doped CdS nanowires

Sn-doped CdS nanowires exhibit unique magneto-optical properties due to their anisotropic structure and defect-mediated exciton behavior. In this work, Sn-doped CdS nanowires were successfully prepared by CVD, and their photoluminescence behavior was systematically investigated under magnetic field, temperature, and laser power modulation. Variable-temperature PL spectra show that elevated temperature leads to thermal dissociation of excitons and lattice expansion, which triggers peak redshift and non-radiative recombination enhancement. At low temperature (1.7 K), the intensities of both the band-edge emission peaks (∼500<i>n</i><i>m</i>) and the defect state emission peaks (550-600 nm) are significantly higher than those at room temperature (300 K). The magneto-optical anisotropy of Sn-doped CdS is significantly revealed by the modulation of the magnetic field polarization degree; through the Zeeman splitting and spin-polarization effects, the polarization degree of the band-edge emission can be modulated in the range of -0.4 to 0.8. Our results will contribute to the understanding of the competition and coupling mechanism between exciton and defect states in Sn-doped CdS.